Many of us have been there, the doctor is staring at us straight into our soul telling us we are “overweight” or even “obese” according to BMI standards. You’re fit, you workout, you eat really well, and you look dang good but the doctor is still telling you you’re “overweight.” This can be such a buzz kill, but it is important for us to understand what BMI actually is, and why it is an outdated system that we shouldn’t use to measure our health.


What is BMI?

BMI which stands for Body Mass Index is a standard assessment tool used in most healthcare facilities. It has been used for decades as a way to determine health based upon size, but has been very widely criticized because of the way that it oversimplifies the statement of being “healthy.” BMI is calculated with a formula that determines whether a person is a “healthy” weight by dividing their weight in kilograms by their height in meters squared. Once you determine what your BMI is, you can check out the scale to see what weight range that you fall into, and if your BMI is normal or not.


When is BMI a good measure of health?

Though in most cases BMI doesn’t accurately depict whether a person is healthy or not, there have been numerous studies done that show a person with a BMI under 18.5, and a BMI over 30 are at a higher risk to developing chronic disease or dying prematurely.Due to most research showing an increased chronic disease risk among people with obesity, many health professionals can use BMI as a general snapshot of a person’s risk. Still, it should not be the only diagnostic tool used.


Why is BMI not an accurate representation of health?

BMI doesn’t consider other factors of health: BMI only considers whether a person is a “healthy” weight or not. It does not consider other factors like age, gender, lifestyle, genetics, medical history and so on. BMI can miss important factors about a persons health for example if they have high cholesterol, high blood pressure, etc. In addition to this, like mentioned at the beginning of this paragraph, GENDER! With BMI, they use the same calculator for both men and women which is not accurate since for obvious reasons men and women’s body compositions are very different. Men tend to have a higher muscle mass, and less body fat and women usually carry a bit more body fat.

BMI assumes all weight is equal: One pound of muscle and one pound of fat weigh the same, but muscle is more dense and takes up less space. A person can be VERY lean, but have a ugh muscle mass which will make them heavier on the scale. For example, a man who is 200lbs, and 5′ 9″ who has a BMI of 29.5 is classified as overweight according to BMI. However, two people of the same height and weight could look completely different. One could be a body builder with a high muscle mass, and one could have a higher body fat percentage. BMI doesn’t consider body fat percentage, muscle mass, and bone mass. BMI could easily consider somebody over weight, or even obese who truly has a super low fat percentage and a very high muscle mass. For example “The Rock” is considered “obese” by the BMI scale even though he is pure muscle with a very low body fat percentage.


Are there better alternatives?

There are many alternatives to BMI, however like anything they all come with their own set of advantages, and disadvantages. Body Fat Percentage is a tool that we can use here at the gym to help get a better idea of where you are at “health” wise.

Body Fat Percentage: This measurement shows us the relative amount of fat that a person has on their body. This tool distinguishes between fat mass, and fat free mass. It can be a more accurate representation of health risk than BMI. The major disadvantage of this one is that there is really no formula to figure out your body fat percentage, there are only tools. These tools are scales and skinfold measurements and are not always accurate. They have a high level of error. There are more accurate, but also more expensive ways to measure body fat such as the BodPod, under water weighing, and dual energy x-ray’s. Though these are the most accurate tools, they are not accessible to all because of the high cost associated with them. Here a the gym we use the “inbody” scanner which uses the bio-electric impedance analysis. The inbody scale provides a comprehensive review of our body composition.


The Bottom Line:

Ultimately, BMI is a highly controversial tool used in health assessments to estimate a persons body fat and risk of poor health. Research shows that those with high range BMI, or even those below average are at greater risk of chronic illness. With that being said, BMI fails to consider other aspects of a person’s health. BMI has caused a horrible stigma for doctors, and many people dread going to the doctors because they don’t want to be called “obese” according to the BMI scale. It can be a helpful starting point, but other factors should always be considered when determining true “health.”